People sometimes ask me why Google itself doesn't use GWT, but many people don't realize that many of Google's newer services are written using it.

Some Google products that use Google Web Toolkit that you may not know about:

AdWords http://google.com/adwords
AdSense http://google.com/adsense
Flights http://flights.google.com
Hotel Finder http://www.google.com/hotelfinder
Offers https://www.google.com/offers
Wallet http://wallet.google.com
The New Blogger http://www.blogger.com/
Chrome Webstore https://chrome.google.com/webstore (Actually done in Closure, but embeds GWT checkout code)
Product Search http://www.google.com/prdhp?hl=en&tab=mf
Public Data http://www.google.com/publicdata/home
New Google Groups http://groups.google.com
Orkut http://www.orkut.com
Google Health (discontinued)
Google Wave (discontinued)
PlayN (basis of Angry Birds)
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